1. Applications and Technical Specifications
1.1 Applications
The hydraulic control butterfly valve is operated by a hydraulic power unit and represents a new generation of hydraulically actuated butterfly valves.
It combines the functions of a shut-off valve and a check valve in a single unit. Through a programmed two-stage closing mechanism, the valve effectively controls water hammer and pressure surges caused by sudden power failures or unexpected pump shutdowns.
This design significantly reduces the impact of water hammer on pumps, pipelines, and associated equipment, ensuring safe and reliable operation of pumping stations and water supply systems.
1.2 Technical Specifications
| Parameter | Specification |
|---|---|
| Nominal Diameter | DN600–DN3000 |
| Nominal Pressure | PN 1.0 MPa |
| Shell Test Pressure | 1.5 MPa |
| Seat Tightness Test Pressure | 1.1 MPa |
| Maximum Operating Temperature | ≤80°C |
| Applicable Media | Water, oil, and other non-corrosive fluids |
2. Model Designation and Applicable Standards
2.1 Model Designation
Example model: HD741H-10C
The model designation is interpreted as follows:
| Code | Description |
|---|---|
| HD | Check butterfly valve |
| 7 | Hydraulic actuation |
| 4 | Flanged connection |
| 1 | Vertical disc configuration |
| H | Stainless steel sealing surface |
| 10 | Nominal pressure: PN10 (1.0 MPa) |
| C | Carbon steel valve body |
2.2 Applicable Standards
The valve is designed and manufactured in accordance with the following standards:
- GB 12221: Face-to-face dimensions of metal valves
- GB 9113: Steel pipe flanges
3. Structure, Features and Operating Principle
3.1 Valve Structure
The hydraulic control butterfly valve mainly consists of three assemblies:
- Main valve body
- Hydraulic power unit
- Electrical control cabinet
The overall configuration and external connections are shown in the corresponding structural drawings.
3.2 Main Design Features
1. Energy-efficient hydraulic actuation
The valve uses a hydraulic accumulator instead of a traditional heavy counterweight to provide the energy required for valve closing.
Compared with conventional counterweight-operated hydraulic control butterfly valves, this design offers several advantages:
- Compact structure and reduced overall dimensions
- Lower equipment weight
- More reliable and stable operation
- Flexible installation arrangements
- Reduced energy consumption
- Improved appearance and simplified maintenance
2. Reliable hydraulic and electrical control systems
The valve is equipped with a comprehensive hydraulic system and a reliable electrical control system, allowing both local and remote operation.
The hydraulic power unit and electrical control cabinet can be installed separately from the main valve body.
The valve can be installed in either horizontal or vertical pipeline configurations, depending on site requirements.
3.3 Valve Opening and Closing Characteristics
The valve uses an accumulator-powered hydraulic system to drive the valve disc through a 90° rotation, enabling controlled opening and closing.
The closing process is divided into two stages: fast closing and slow closing. This two-stage mechanism minimizes pressure fluctuations and reduces the risk of water hammer.
The closing characteristics can be adjusted by regulating the hydraulic flow control valves.
Recommended adjustment settings:
- Fast-closing time: 5 seconds
- Slow-closing time: 15 seconds
- Fast-closing angle: 90° to approximately 25°
- Slow-closing angle: approximately 25° to 0°
The fast-closing and slow-closing stages can be adjusted according to the operating requirements of the pumping system.
Typical closing parameters
| Parameter | DN ≤1200 | DN ≥1400 |
|---|---|---|
| Valve opening time | 20–60 s | 30–120 s |
| Fast-closing time | 2–3.0 s | 2.5–3.0 s |
| Slow-closing time | 2–60 s | 5–60 s |
| Fast-closing angle | 65° ±10° | 65° ±10° |
| Slow-closing angle | 25° ±10° | 25° ±10° |
The closing speed and angular transition can be adjusted through the hydraulic flow control valves.
4. Hydraulic Operating Principle
4.1 Hydraulic Power Unit Startup
After the electrical system is energized, the hydraulic pump motor starts and drives the hydraulic pump.
Hydraulic oil flows through the hydraulic circuit, including the check valves and filters, and enters the accumulator.
A pressure switch monitors the accumulator pressure.
When the accumulator reaches the preset upper pressure limit, the hydraulic pump stops automatically.
When the pressure drops below the preset lower limit, the pressure switch sends a signal to restart the hydraulic pump, maintaining the required system pressure.
This automatic pressure control ensures sufficient stored hydraulic energy for reliable valve operation.
4.2 Valve Opening
When the valve opening command is activated, the corresponding solenoid valves are energized.
Pressurized hydraulic oil from the accumulator flows through the control circuit and enters the appropriate chamber of the hydraulic cylinder.
The hydraulic cylinder drives the piston rod, which rotates the valve disc through the transmission mechanism.
The butterfly valve gradually opens until it reaches the fully open position.
The opening speed can be adjusted through the relevant hydraulic flow control valve.
Once the valve reaches the required opening position, the electrical control system maintains the appropriate operating state.
4.3 Valve Closing
When the closing command is activated, the solenoid valves switch to the closing position.
Hydraulic pressure acts on the actuator, driving the valve disc toward the closed position.
The valve closes in two stages:
Stage 1: Fast Closing
During the initial closing stage, hydraulic oil passes through the fast-closing flow control circuit.
The valve disc rotates rapidly from the fully open position toward the preset transition angle.
This reduces reverse flow and limits the initial pressure surge caused by pump shutdown.
Stage 2: Slow Closing
After reaching the transition angle, the hydraulic circuit switches to the slow-closing stage.
The valve disc continues rotating at a controlled, reduced speed until the valve is fully closed.
This process minimizes water hammer and protects pumps, pipelines, and related equipment.
The fast-closing angle, slow-closing angle, and closing times can be adjusted according to actual operating conditions.
4.4 Emergency Stop and Position Holding
During valve opening or closing, the operator can press the stop button to interrupt the operation.
The solenoid valves are de-energized, and the hydraulic circuit holds the actuator in position.
The valve can therefore remain at an intermediate opening angle when required.
This function provides additional operational flexibility during commissioning, adjustment, and maintenance.
4.5 Manual Operation and Emergency Hydraulic Control
If the electrical hydraulic pump fails or cannot operate normally, the hydraulic accumulator can be charged using the manual pump.
The operator can manually increase the accumulator pressure to the required level and then perform valve opening or closing through the appropriate control circuit.
This emergency operating function improves system reliability and allows valve operation when electrical power or the main hydraulic pump is unavailable.
4.6 Automatic Accumulator Pressure Compensation
During extended operation, minor internal leakage in the hydraulic system may gradually reduce accumulator pressure.
When the pressure drops to the preset lower limit, the pressure switch sends a signal to start the hydraulic pump automatically.
The pump replenishes the accumulator until the pressure reaches the preset upper limit.
The pump then stops automatically.
This pressure compensation function maintains sufficient hydraulic energy for valve operation and helps ensure long-term system reliability.
5. Key Advantages of the New Generation Hydraulic Control Butterfly Valve
The new generation hydraulic control butterfly valve provides an integrated solution for flow control, pump protection, and water hammer prevention.
Its main advantages include:
- Integrated shut-off and check functions: Combines two functions in one valve, simplifying pipeline arrangements.
- Water hammer protection: Two-stage controlled closing helps minimize pressure surges during unexpected pump shutdowns.
- Accumulator-powered operation: Eliminates the need for large external counterweights and improves installation flexibility.
- Adjustable operating characteristics: Opening and closing times can be adjusted to match specific pumping system requirements.
- Automatic pressure maintenance: Maintains hydraulic accumulator pressure through automatic pump control.
- Flexible installation: Suitable for horizontal and vertical pipeline arrangements.
- Local and remote control: Supports automated operation and centralized monitoring.
- Emergency operation: Manual hydraulic pumping provides an alternative when the main power unit is unavailable.
6. Typical Applications
Hydraulic control butterfly valves are widely used in large-diameter water supply and industrial pipeline systems where reliable pump protection and controlled valve operation are required.
Typical applications include:
- Municipal water supply and distribution systems
- Water pumping stations
- Industrial circulating water systems
- Water treatment plants
- Power plant cooling water systems
- Large-diameter water transmission pipelines
- Pump discharge pipelines requiring water hammer protection
Conclusion
The new generation hydraulic control butterfly valve combines hydraulic actuation, automatic pressure control, and adjustable two-stage closing technology in a compact and reliable design.
By integrating shut-off and check valve functions, it helps reduce water hammer, protect pumping equipment, and improve the safety and stability of pipeline systems.
Its flexible installation options, reliable hydraulic control system, and emergency operating capabilities make it a practical solution for modern water supply, pumping station, and industrial fluid control applications.
